A fingerprint unlocking function is a convenient and practical biometric identification technique, and is widely used in terminal devices such as smartphones and the like. To enhance user experiences, in some existing terminal devices, a pressure sensor function is further integrated into a fingerprint module, so that the fingerprint module can identify a value of the pressure applied on the fingerprint module, and instruct a control chip to trigger a corresponding function according to the value of the pressure.
Generally, the pressure sensor is manufactured based on a flexible circuit board and is usually directly adhered to a lower surface of a reinforcing steel sheet of a fingerprint module via an adhesive. The reinforcing steel sheet is used mainly for improving the strength of the fingerprint module. However, with such a structure, an overall thickness of the fingerprint module is greatly increased (the thickness is increased by at least 0.15 millimeters), which therefore affects an overall thickness of the terminal device and the development towards an ultra-thin device.